[Intel-gfx] [PATCH v10 07/40] drm/i915: hdcp1.4 CP_IRQ handling and SW encryption tracking

C, Ramalingam ramalingam.c at intel.com
Thu Jan 31 13:41:11 UTC 2019



On 1/31/2019 1:26 PM, Daniel Vetter wrote:
> On Thu, Jan 31, 2019 at 12:29:23PM +0530, Ramalingam C wrote:
>> "hdcp_encrypted" flag is defined to denote the HDCP1.4 encryption status.
>> This SW tracking is used to determine the need for real hdcp1.4 disable
>> and hdcp_check_link upon CP_IRQ.
>>
>> On CP_IRQ we filter the CP_IRQ related to the states like Link failure
>> and reauthentication req etc and handle them in hdcp_check_link.
>> CP_IRQ corresponding to the authentication msg availability are ignored.
>>
>> WARN_ON is added for the abrupt stop of HDCP encryption of a port.
>>
>> v2:
>>    bool is used in struct for the cleaner coding. [Daniel]
>>    check_link work_fn is scheduled for cp_irq handling [Daniel]
> Just doing a delta-review, v2 addresses my comment about synchronization
> with the worker, so
>
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Thank you.

--Ram
>
>> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>> ---
>>   drivers/gpu/drm/i915/intel_dp.c   |  2 +-
>>   drivers/gpu/drm/i915/intel_drv.h  |  5 ++-
>>   drivers/gpu/drm/i915/intel_hdcp.c | 73 ++++++++++++++++++++++++++++-----------
>>   3 files changed, 58 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index 815ee68efa2f..9ce05819fc11 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -4776,7 +4776,7 @@ static void intel_dp_check_service_irq(struct intel_dp *intel_dp)
>>   		intel_dp_handle_test_request(intel_dp);
>>   
>>   	if (val & DP_CP_IRQ)
>> -		intel_hdcp_check_link(intel_dp->attached_connector);
>> +		intel_hdcp_handle_cp_irq(intel_dp->attached_connector);
>>   
>>   	if (val & DP_SINK_SPECIFIC_IRQ)
>>   		DRM_DEBUG_DRIVER("Sink specific irq unhandled\n");
>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>> index 63e009286d5f..13a41e8cf4ff 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -399,6 +399,9 @@ struct intel_hdcp {
>>   	struct delayed_work check_work;
>>   	struct work_struct prop_work;
>>   
>> +	/* HDCP1.4 Encryption status */
>> +	bool hdcp_encrypted;
>> +
>>   	/* HDCP2.2 related definitions */
>>   	/* Flag indicates whether this connector supports HDCP2.2 or not. */
>>   	bool hdcp2_supported;
>> @@ -2073,10 +2076,10 @@ int intel_hdcp_init(struct intel_connector *connector,
>>   		    bool hdcp2_supported);
>>   int intel_hdcp_enable(struct intel_connector *connector);
>>   int intel_hdcp_disable(struct intel_connector *connector);
>> -int intel_hdcp_check_link(struct intel_connector *connector);
>>   bool is_hdcp_supported(struct drm_i915_private *dev_priv, enum port port);
>>   bool intel_hdcp_capable(struct intel_connector *connector);
>>   bool is_hdcp2_supported(struct drm_i915_private *dev_priv);
>> +void intel_hdcp_handle_cp_irq(struct intel_connector *connector);
>>   
>>   /* intel_psr.c */
>>   #define CAN_PSR(dev_priv) (HAS_PSR(dev_priv) && dev_priv->psr.sink_support)
>> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
>> index e0bb5f32ba90..c1b057f1501b 100644
>> --- a/drivers/gpu/drm/i915/intel_hdcp.c
>> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
>> @@ -74,6 +74,16 @@ bool intel_hdcp_capable(struct intel_connector *connector)
>>   	return capable;
>>   }
>>   
>> +static inline bool intel_hdcp_in_use(struct intel_connector *connector)
>> +{
>> +	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> +	enum port port = connector->encoder->port;
>> +	u32 reg;
>> +
>> +	reg = I915_READ(PORT_HDCP_STATUS(port));
>> +	return reg & HDCP_STATUS_ENC;
>> +}
>> +
>>   static int intel_hdcp_poll_ksv_fifo(struct intel_digital_port *intel_dig_port,
>>   				    const struct intel_hdcp_shim *shim)
>>   {
>> @@ -668,6 +678,7 @@ static int _intel_hdcp_disable(struct intel_connector *connector)
>>   	DRM_DEBUG_KMS("[%s:%d] HDCP is being disabled...\n",
>>   		      connector->base.name, connector->base.base.id);
>>   
>> +	hdcp->hdcp_encrypted = false;
>>   	I915_WRITE(PORT_HDCP_CONF(port), 0);
>>   	if (intel_wait_for_register(dev_priv, PORT_HDCP_STATUS(port), ~0, 0,
>>   				    ENCRYPT_STATUS_CHANGE_TIMEOUT_MS)) {
>> @@ -713,8 +724,10 @@ static int _intel_hdcp_enable(struct intel_connector *connector)
>>   	/* Incase of authentication failures, HDCP spec expects reauth. */
>>   	for (i = 0; i < tries; i++) {
>>   		ret = intel_hdcp_auth(conn_to_dig_port(connector), hdcp->shim);
>> -		if (!ret)
>> +		if (!ret) {
>> +			hdcp->hdcp_encrypted = true;
>>   			return 0;
>> +		}
>>   
>>   		DRM_DEBUG_KMS("HDCP Auth failure (%d)\n", ret);
>>   
>> @@ -741,16 +754,17 @@ int intel_hdcp_check_link(struct intel_connector *connector)
>>   	enum port port = intel_dig_port->base.port;
>>   	int ret = 0;
>>   
>> -	if (!hdcp->shim)
>> -		return -ENOENT;
>> -
>>   	mutex_lock(&hdcp->mutex);
>>   
>> -	if (hdcp->value == DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
>> +	/* Check_link valid only when HDCP1.4 is enabled */
>> +	if (hdcp->value != DRM_MODE_CONTENT_PROTECTION_ENABLED ||
>> +	    !hdcp->hdcp_encrypted) {
>> +		ret = -EINVAL;
>>   		goto out;
>> +	}
>>   
>> -	if (!(I915_READ(PORT_HDCP_STATUS(port)) & HDCP_STATUS_ENC)) {
>> -		DRM_ERROR("%s:%d HDCP check failed: link is not encrypted,%x\n",
>> +	if (WARN_ON(!intel_hdcp_in_use(connector))) {
>> +		DRM_ERROR("%s:%d HDCP link stopped encryption,%x\n",
>>   			  connector->base.name, connector->base.base.id,
>>   			  I915_READ(PORT_HDCP_STATUS(port)));
>>   		ret = -ENXIO;
>> @@ -791,18 +805,6 @@ int intel_hdcp_check_link(struct intel_connector *connector)
>>   	return ret;
>>   }
>>   
>> -static void intel_hdcp_check_work(struct work_struct *work)
>> -{
>> -	struct intel_hdcp *hdcp = container_of(to_delayed_work(work),
>> -					       struct intel_hdcp,
>> -					       check_work);
>> -	struct intel_connector *connector = intel_hdcp_to_connector(hdcp);
>> -
>> -	if (!intel_hdcp_check_link(connector))
>> -		schedule_delayed_work(&hdcp->check_work,
>> -				      DRM_HDCP_CHECK_PERIOD_MS);
>> -}
>> -
>>   static void intel_hdcp_prop_work(struct work_struct *work)
>>   {
>>   	struct intel_hdcp *hdcp = container_of(work, struct intel_hdcp,
>> @@ -1120,6 +1122,18 @@ int hdcp2_deauthenticate_port(struct intel_connector *connector)
>>   	return hdcp2_close_mei_session(connector);
>>   }
>>   
>> +static void intel_hdcp_check_work(struct work_struct *work)
>> +{
>> +	struct intel_hdcp *hdcp = container_of(to_delayed_work(work),
>> +					       struct intel_hdcp,
>> +					       check_work);
>> +	struct intel_connector *connector = intel_hdcp_to_connector(hdcp);
>> +
>> +	if (!intel_hdcp_check_link(connector))
>> +		schedule_delayed_work(&hdcp->check_work,
>> +				      DRM_HDCP_CHECK_PERIOD_MS);
>> +}
>> +
>>   static int i915_hdcp_component_bind(struct device *i915_kdev,
>>   				    struct device *mei_kdev, void *data)
>>   {
>> @@ -1288,7 +1302,8 @@ int intel_hdcp_disable(struct intel_connector *connector)
>>   
>>   	if (hdcp->value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
>>   		hdcp->value = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
>> -		ret = _intel_hdcp_disable(connector);
>> +		if (hdcp->hdcp_encrypted)
>> +			ret = _intel_hdcp_disable(connector);
>>   	}
>>   
>>   	mutex_unlock(&hdcp->mutex);
>> @@ -1328,3 +1343,21 @@ void intel_hdcp_atomic_check(struct drm_connector *connector,
>>   						   new_state->crtc);
>>   	crtc_state->mode_changed = true;
>>   }
>> +
>> +/* Handles the CP_IRQ raised from the DP HDCP sink */
>> +void intel_hdcp_handle_cp_irq(struct intel_connector *connector)
>> +{
>> +	struct intel_hdcp *hdcp = &connector->hdcp;
>> +
>> +	if (!hdcp->shim)
>> +		return;
>> +
>> +	/*
>> +	 * CP_IRQ could be triggered due to 1. HDCP2.2 auth msgs availability,
>> +	 * 2. link failure and 3. repeater reauth request. At present we dont
>> +	 * handle the CP_IRQ for the HDCP2.2 auth msg availability for read.
>> +	 * To handle other two causes for CP_IRQ we have the work_fn which is
>> +	 * scheduled here.
>> +	 */
>> +	schedule_delayed_work(&hdcp->check_work, 0);
>> +}
>> -- 
>> 2.7.4
>>



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